A timeline of all major events in the Halo universe from the time of the Forerunners through the rule of the Created.
The Harvest Campaign was a five-year campaign to retake the planet Harvest after the Covenant took over the planet and wiped out the colony on Harvest.
The Battle of the Rubble was a battle that took place in the 23 Librae system on a grouping of Lagrangian asteroids trailing Hesiod, a gas giant in the system, some time around 2535.
The Skirmish on Mona Lisa was a minor conflict that occurred in the debris field of Installation 04 in the Soell system aboard the prison ship Mona Lisa between UNSC forces and an outbreak of the Flood on October 25th, 2552.
Operation: ATHENA was a covert UNSC mission to infiltrate the Song of Retribution, and retrieve the Janus Key from Jul 'Mdama and his Covenant remnant forces in September 2558.
